My computer updated when I was responding to great response I got from those kind enough to help and I lost everything. I'm starting over again. Sorry. A bleeder-valve to let air into water line was placed under second-floor vanity in bathroom to feed the 16 inch frost-free facet in the garage. We could not find the valve to use garden hose and builder told us it was under the vanity, but did not explain to us that there was a bleeder. We opened the valve, watered new law, next day the bottom floor was flooded out with extensive damage. The plumber had the frost-free valve shut, which is good, but the bleeder-valve open, so I estimate that the water backed up all the way to our upstairs vanity and leaked water? Questions:

Should a bleeder-valve leak? Do you even need a bleeder valve if there is a frost-free facet installed? Should a second-floor bathroom even be used to feed an outdoor facet? Should a bleeder-valve be installed horizontal instead of vertical? Ours is vertically installed and on a 45 degree upward slope.

Also, I would like to add that the plumber connected to the water supply to the upstairs bathroom with 60 psi of pressure coming from the pressure tank in the downstairs utility room. Wouldn't 60 psi be sufficient enough to drain water from the line without a bleeder-valve anyway? And, would the 60 psi cause the bleeder valve to leak or malfunction?

One more issue: The sewage coming from our house goes through a 4 inch PVC pipe, through the utility room wall, and out to the septic system. Against the utility room wall, about three feet off the floor, is a plug? If the sewage was to back-up in our tank and we were to open the plug, the sewage would come into the house. Wouldn't it be better to have a shut-off valve instead of a plug--then you could close the valve and get the septic tank pumped-out. And, wouldn't it be better still, to have a shut-off valve mechanism outside of the house rather than on the inside?

I would like to thank all responders in advance. Your input is greatly appreciated.


3 Answers 3



In this case, a bleeder valve is used to protect outdoor faucets from damage during freezing weather.

Pre-winter, you turn off water to the outdoor faucet, you open the outdoor faucet and then open the bleeder valve to let the water drain out.

In the summer, you close the bleeder valve, you close the outdoor faucet and then turn on water to the outdoor faucet, restoring it to normal use.

I'm guessing you had the outdoor faucet replaced with one that keeps the valve portion inside the house (where it's warm) while the handle of the faucet is still outside.

They left the bleeder valve in place...but it was in the open position...oops.

  • Steve, thank you very much for your response. Guess what? No, we didn't get the plumber to place a frost-free facet in our garage as an upgrade, this was a new build, a new home, and this is what the plumber installed to start with. Why a bleeder-valve? Why not feed the garage facet with shut-off valve in utility room on first floor near floor-drain to eliminate problems like this? Apr 8, 2021 at 14:12
  • 1
    Why not, @williamTerranceCole? You'd probably have to ask your builder.
    – FreeMan
    Apr 8, 2021 at 15:55

In the fall you would ordinarily:

  1. Close the supply valve and leave it closed.
  2. Open the outside faucet and leave it open.
  3. Open the bleeder and leave it open.

The purpose of the bleeder is to allow air to flow in as the water drains rather than having a vacuum created that might prevent the line from emptying completely.

The purpose of leaving the various pieces configured that way during cold weather is that if there is a slight leak at the supply valve then water can run out of the outside faucet rather than refilling the line and possibly freezing and bursting the pipe.

In warm weather the process is reversed: Close the bleeder, close the outside faucet and open the supply valve.

One can imagine various failure modes:

  1. The bleeder might be located, e.g. on the bottom of the supply valve, such that any leakage at the supply valve will immediately run out of the bleeder. You'll need to leave it closed or arrange for safe drainage. (The orientation of a bleeder depends on what it is supposed to bleed (Water from above or a vacuum breaker for plumbing below.), whether it is integrated into a valve body or a separate device, space available, ... . Photographs would help us assess the goodness of your particular configuration.)
  2. Someone might inadvertently close the outside faucet and there might be a leak in the supply valve. The line would refill and eventually start leaking through the bleeder.
  3. A small leak at the supply valve may cause enough ice to build up on the outside faucet to block the outflow. The line would refill and eventually start leaking through the bleeder.
  4. The bleeder could fail to seal completely and leak after the supply valve is opened.

All of the systems I've encountered with bleeders would either whistle while expelling air or spray water if the supply valve was opened with the bleeder open.

In any event, the takeaway is to check all of the valves immediately after completing the work, somewhat later and again the next day. It is common for infrequently used valves to leak at the valve stem, and the bleeder or outside faucet may be in need of new seals/washers. Feel around each component and check for any leaks before they become problematic.

Note that with the supply valve closed the pressure of the water supply has no effect on draining the line.

A leak alarm in the vanity (and various other places) may also be a good idea. It doesn't matter whether the water is coming from the bleeder or a bad seal between the faucet and the vanity top, any water on the base of the vanity is a bad thing. Tossing one in the vicinity of disposers, dishwashers, washing machines and the like isn't a bad idea. Each has its own ways to fail, e.g. fur and lint blocking the washing machine drain or a supply hose failing. I've had success with Leak Frogs and there are plenty of similar devices available. (Disclaimer: No financial relationship, just a happy customer.)

If there is a toilet or bath/shower on the same floor as the utility room you would likely know about a sewer backup before it is three feet above floor level. The plug is a "clean out" which provides (relatively) convenient access for snaking the the line from the house to the septic tank. A shutoff is likely illegal and provides more opportunities for misadventure. A check valve might be allowed, but can be problematic in an unpressurized line carrying non-fluid materials.

  • HABO, your mother would be proud. The builder told us to open the valve in the vanity in the second floor bathroom with no mention of a bleeder. We opened the valve and used the garden hose all day. The next day the bottom floor was flooded. I checked in the vanity and the bleeder was spraying water. We want the builder to place the feed to the facet in the garage on the bottom floor where it should have been in the first place. Thanks for your response. Apr 8, 2021 at 17:01
  • @williamTerranceCole My mother would be confused. The last time a Leak Frog went off at her house she started opening doors and windows so the cricket could get out. It seems that hearing and memory sometimes begin to decline after age 90. (I didn't bother waiting that long.) I make a habit of checking any shutoff valve several times after using it, regardless of whether it is left open or closed. Many a vintage vanity or toilet shutoff has slowly dripped just because I was fool enough to touch it, even if only to check that it was fully open.
    – HABO
    Apr 8, 2021 at 18:30

Is a bleeder-valve to let air into the water line necessary when the plumber put in a frost-free valve?

NO it is not necessary.

If you have a frost free hose bib then it is not necessary to bleed the supply line to it to prevent freezing. A frost free hose bib has the handle on the exterior of the house but the valve it controls is inside the heated space. When you close the hose bib the water left in the pipe between the valve and the handle drains out so there is no water in the outdoor portion of it to freeze.

Should a bleeder-valve leak if kept open?

Will it leak?, Yes if you leave it open and then turn on the valve without closing the bleeder port.

Should it leak? No, If the valve is off and there is no water left in the line.

"Should" is not the right way to think about it, plumbing supply lines should NOT leak.

With your set up the valve/with bleeder, is above the hose bib and the bleeder port is there to break a vacuum seal in order to let the water drain out. (the water in the pipe between the valve/with bleeder and the hose bib)

In your case, to drain the line you would

  • Close the supply line valve that has the bleeder, (valve/with bleeder)

  • Then go open the hose bib,

  • Then go back and open the bleeder port.

  • After the line has been drained you can close the bleeder port (leave the valve closed), and go close the hose bib.

This set of steps allows the water in the line to drain out of the hose bib and then sets everything up so that when warmer weather arrives all you have to do is open the valve/with bleeder. (remember, you closed the bleeder, but check it again before opening the valve/with bleeder)

To reiterate:

After the supply line is empty, drained of water, it is not necessary to leave the bleeder port open as the line has been drained. You can go close the hose bib and then go back and close the bleeder port, as it has served its purpose, but leave the valve it is on closed so no water will supplied to the hose bib. Always check a bleeder port on a valve before turning on the valve.

  • Alaska Man, you have certainly imparted some wisdom here today. If the plumber had of taken the time, as you have with me today, our home wouldn't have been flooded out. We never even heard of a bleeder on a valve till after the disaster. Thank you so much for your time. Keep imparting wisdom, you're helping a lot of people. Apr 9, 2021 at 13:00

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